Two-Qubit Interaction Encoding With Bacon-Shor Noise Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current quantum computing systems face challenges in effectively suppressing noise during quantum annealing processes, particularly in maintaining the integrity of qubits, which affects the accuracy and reliability of quantum computations.
Innovation Solution
The implementation of Bacon-Shor Hamiltonian encoding, utilizing two-qubit interactions and tunable couplers, creates logical qubits that are resistant to noise, leveraging the quantum compass model to protect quantum information and enable fault-tolerant quantum memory by using edge coupling between qubits on a two-dimensional lattice.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum annealing is performed with standard qubit encoding, then the quantum computation can proceed, but noise effectively degrades the reliability of the quantum states
Solution Approach 1:
The patent divides a logical qubit into multiple physical qubits (e.g., five physical qubits per logical qubit) arranged in a specific lattice pattern. This segmentation allows the quantum information to be distributed and protected across multiple physical carriers, reducing the impact of noise on any single qubit and improving overall computation reliability.
Solution Approach 2:
The patent employs composite quantum states formed by combining multiple physical qubits into encoded logical qubits using Bacon-Shor code. This composite structure creates noise-resistant quantum states that maintain integrity during annealing, effectively suppressing harmful noise while preserving computational functionality.
2Reliability
If the coupling strength between qubits is increased to suppress noise, then error suppression improves, but the system complexity and control difficulty increase
Solution Approach 1:
The patent implements different coupling strengths for different pairs of qubits within the encoded logical qubit structure. Specifically, certain qubit pairs have stronger coupling while others have weaker coupling, creating a non-uniform coupling pattern that optimizes noise suppression while maintaining manageable system complexity through localized differentiation.
Solution Approach 2:
The patent employs tunable couplers that can dynamically adjust coupling strength during the quantum annealing process. This dynamic control allows the system to optimize coupling parameters in real-time, achieving effective noise suppression without requiring permanently high coupling strengths that would increase hardware complexity.
3Reliability
If Bacon-Shor encoding with multiple physical qubits per logical qubit is implemented, then noise resistance improves, but the number of physical qubits required increases
Solution Approach 1:
The patent segments quantum information into distributed representations across physical qubits using Bacon-Shor code, where each logical qubit is encoded in multiple physical qubits. This segmentation provides redundancy and error protection, achieving noise resistance with a practical number of physical qubits rather than requiring excessive resources.
Solution Approach 2:
The patent optimizes the encoding parameters of the Bacon-Shor code (such as the number of physical qubits per logical qubit and the specific coupling patterns) to achieve effective noise suppression with a minimized number of physical qubits. By carefully selecting and tuning these parameters, the system achieves noise resistance without linearly increasing the physical qubit count.
Data Source
Figure 1~4
Figure 2
Figure 3
AI summary
Systems and methods are provided for encoding two-qubit interactions. A quantum circuit comprises first and second logical qubits, each comprising a Bacon-Shor code block. A first edge of each logical qubit contains physical qubits each coupled to at least one neighboring physical qubit along the first edge along a first axis of the Bloch sphere and a second edge of each logical qubit contains physical qubits each coupled to at least one neighboring physical qubit along the second edge along a second axis of the Bloch sphere. A set of couplers couple the first and second logical qubits along the first axis of the Bloch sphere, with each of the set of couplers coupling a physical qubit along the second edge of the first logical qubit to a corresponding physical qubit along the second edge of the second logical qubit along the first axis of the Bloch sphere.